In designing and building freezers, coolers, and food processing facilities wherein temperature control is important, one of the main challenges is the creation of a building envelope that provides maximum efficiency of heating, ventilating, and air conditioning (HVAC), while controlling the transfer of condensation and vapor within a secure, sanitary environment. A conventional wall for such facilities has been built with insulated metal panels. However, such metal panels are not energy efficient due to a lack of mass that can create a thermal lag effect that can compensate for wide temperature fluctuations. Metal panels also have an inherent lack of security due to the thin metal skin of the panels, which can be easily punctured, for example by a fork lift blade. Finally, metal panels have low fire resistance, and therefore can lead to high insurance costs.
Concrete panels have also been used for building freezers, coolers, and food processing facilities. Typically, the concrete panels include two concrete layers between which is sandwiched an insulation layer of extruded polystyrene foam. Fiber composite connectors bond the multi-layered wall together so as to provide an energy efficient and secure building structure. However, such concrete panels may have problems with condensation and vapor transfer, particularly at the joints between adjacent panels and through the connector holes in the insulation. Also, the concrete layers tend to bond with the foam layer, thereby preventing or detrimentally affecting the desirable relative movement between the concrete and the foam during thermal expansion and contraction.
Therefore, a primary objective of the present invention is the provision of an improved thermally efficient wall structure.
Another objective of the present invention is the provision of a multi-layer concrete wall panel having a vapor barrier.
A further objective of the present invention is the provision of an improved insulation layer for a concrete wall panel.
A further objective of the present invention is the provision of a channel on the edge of a concrete wall panel to which a vapor film can be easily attached.
Still another objective of the present invention is the provision of a method of forming a wall structure to prevent bonding between the insulation layer and adjacent concrete layers.
Another objective of the present invention is the provision of a vapor barrier device for use between adjacent panels of a building structure.
A further objective of the present invention is the provision of a method of forming a wall structure having a vapor barrier.
These and other objectives will become apparent from the following description of the invention.